function getXMLHttpRequest() {
	var xhr = null;

	if (window.XMLHttpRequest || window.ActiveXObject) {
		if (window.ActiveXObject) {
			try {
                            xhr = new ActiveXObject("Msxml2.XMLHTTP");
			} catch(e) {
                            xhr = new ActiveXObject("Microsoft.XMLHTTP");
			}
		} else {               
                    xhr = new XMLHttpRequest();
		}
	} else {
            alert("Votre navigateur ne supporte pas l'objet XMLHTTPRequest...");
            return null;
	}
        
	return xhr;
}